Numerous methods, processes, and catalysts have been described for alkylating aromatic amines to provide valuable and useful chemical products. However, the previous suggestions have various defects including lack of selectivity of the desired product, poor conversion of the aromatic amine, and excessive deterioration of the alkylating agent which then cannot be recovered for recycle or other use.
My prior copending application Ser. No. 618,005, filed June 6, 1984 describes, inter alia, a process which comprises the step of reacting (a) an aromatic amine having at least one replaceable hydrogen atom on an amine group or on an aromatic ring carrying an amino group or both, with (b) an ether in the presence of a B-subgroup metal oxide alkylation catalyst so that alkylation of the aromatic amine occurs. In that application it is disclosed that such cyclic ethers as tetrahydrofuran, tetrahydropyran and their suitably substituted congeners react with primary aromatic amines such as aniline and nuclear alkylanilines (e.g., toluidines, xylidines, o-, m-, p-ethylaniline, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-and 3,5-diethylanilines, etc.) whereby gem-dialkylation of the nitrogen atom occurs and N-arylated cyclic amines are formed. This reaction has now been found to apply to various additional reactant combinations beyond primary aromatic amines and cyclic ethers such as tetrahydrofuran, tetrahydropyran and their suitably substituted congeners. The expanded horizons of the process of this invention will become apparent from the ensuing description and appended claims.